Oral cadmium chloride intoxication in mice: effects of penicillamine, dimercaptosuccinic acid and related compounds.

The antidotal efficacies of chelators during acute cadmium intoxication has previously been examined in experiments where both a soluble cadmium salt and the chelator were administered parenterally. In the present study, PA, DMSA and related compounds were studied as oral antidotes during oral CdCl2 intoxication. According to the antagonistic effects noted on mortality, peristaltic toxicity and intestinal cadmium uptake, the relative efficacies of the compounds tested were: DMSA greater than PAD greater than DMPS greater than MSA greater than PA greater than NAPA. None of the chelators induced major changes in the organ distribution of absorbed cadmium, in particular no increased cerebral deposition of cadmium. This study indicates that, in oral cadmium intoxication in humans, orally administered DMSA would be likely to offer protection against the local toxicity of cadmium in the gastrointestinal tract as well as to reduce the risk of systemic toxicity of absorbed cadmium.